Everyone from college students to mid-career professionals looking for a job change have been told they need to learn how to code. And despite outright detractors and calls for moderation from inside the tech sector, a glut of coding schools has flooded the job market with junior developers.

You’d think that would be good news for tech companies, which now have their pick of newly minted talent. But in many cases it can actually make it harder to develop and maintain a deep bench of tech talent at the senior level–folks who actually stick around, mentor newcomers, and solve the really hairy technical problems more inexperienced coders often can’t.

Too often, the tech industry’s usual slate of perks doesn’t have as much impact when it comes to retaining the most top-shelf, experienced talent. As Stack Overflow COO Jeff Szczepanski wrote for Fast Company recently, “developers care about learning and growing,” but training and professional development aren’t exactly the first things hot new startups rush to talk about when asked about their cultures. In order to stick around, great developers need real career paths; in other words, not just a “hot” job. Here’s a look at a few reasons why your best tech talent might be contemplating an exit, and what it takes to prevent that.

YOU WAITED UNTIL THE EXIT INTERVIEW TO ASK WHAT’S WRONG

The fun of solving problems and the joy of seeing something they’ve built come to life is what drives many software developers. Companies need to leave room for the best of them to keep conceiving of–and then executing–new ideas. “If someone who’s been coming to you with their ideas suddenly stops, it’s a huge sign they’re on the way out the door,” says technology consultant Jason Cole, who advises small businesses on their engineering teams. “If you have someone saying, ‘I’m bored’ and you don’t do something about it, expect them to leave for a place where they won’t be bored.”

These issues don’t usually crop up until somebody’s given their notice and you’re holding an exit interview. But that always means the information you could’ve used to get ahead of the problem arrives too late. That’s why tech leaders should consider holding “stay interviews” with their most valued developers. When the ideas stop flowing or productivity sinks, it’s usually a sign you need to have this type of proactive sit-down.

Diane Scarborough, most recently the interim VP for People and Culture at Sprint Connect, says she’s learned to spot these changes in behavior, however subtle, and unearth unspoken complaints before it’s too late. When talking with team members, she probes for a longing to work on newer technologies and listens for any mentions of friends at other companies working on different projects. Even if these remarks are only made off-handedly, she knows they can be red flags. “Don’t be afraid to ask people questions,” she advises: “Are you happy? What’s making you stay? What would make you leave?”

She adds, “Asking ‘Are you okay?’ isn’t illegal.”

YOU’RE CONFUSING TEACHING WITH MANAGING

The traditional career path is linear, which often means pushing top talent down a management track, supervising others. Leaders may notice that one of their people enjoys teaching others, and then assume that they’d enjoy managing others.

Mentoring and managing might seem similar, but they’re entirely different skills. Management is really about getting work done through others, which makes it highly people-focused. Mentoring or instructing–especially when it comes to software development–is more about a knowledge-transfer of technical skills.

Be careful not to mistake a technical expert who enjoys teaching for one who enjoys managing. Instead, offer your best senior engineers more than just one kind of leadership opportunity; carve out a separate path for technical experts to advance up the ranks based on how well they help their junior colleagues “skill up”–even if that doesn’t involve managing their work.

YOUR ORG CHART ISN’T A LIVING DOCUMENT

Be careful not allow your org chart to become a rigid, set-and-forget artifact–an especially acute risk when it comes to technical roles. Review and adjust your structure to match the expertise of your current team. In Cole’s experience, “the number-one reason technical people quit is because they don’t have the option to advance without going into management.” Szczepanski would likely agree; in his view, developers often get frustrated having to report to leaders who don’t have tech backgrounds themselves.

It’s a perennial problem, but circumventing it can be as simple as reviewing your reporting structure on a regular basis. No matter who leaves and who joins, you always have to make sure there are tech experts in the managerial ranks, and clear paths for other engineers to rise into them.

YOU AREN’T OFFERING ENOUGH SUPPORT

In an attempt to provide flexibility and empower employees, some companies are actually too hands-off–they wind up not giving enough career support. “It’s easy to tell people you’re in charge of your own career,” Scarborough points out, “but it doesn’t work if you don’t support them. Nobody wins if you don’t help them.”

That’s just as true for developers as it is for anyone else, but the risk may be higher when it comes to tech teams, whose expertise can automatically cordon them off from leaders who may not know exactly what they do–or what professional development they might need. On top of that, your engineering team might be so in the weeds with their work they may not be looking at their skills or figure out how they might be applied better.

So rather than making succession planning a once-a-year, check-the-box formality, it’s important to find career development opportunities on a regular basis. Your HR leaders don’t need to have all the answers themselves, either; one of the best ways to offer support is simply to get everyone in a room for an hour and brainstorm ideas for how they can get more of what they want from their work.

Ultimately, building a culture of continuous learning and improvement is what will keep your most valuable senior tech talent on board. And it all starts with having more conversations than you might be, more often. When people can use their talents to do what they love while expanding their skills, they won’t just stay put–they’ll tell their smartest friends to come join them.